Angel Gabriel: What did he do when Jesus was born?

In Nazareth, the Angel Gabriel informed Mary of her immaculate conception and future son the savior. Then when Mary and Joseph had traveled to Bethlehem, Gabriel appeared to shepherds who were watching their sheep nearby. He told them of the newborn king, and how they could recognize him by his swaddling. Then the Angel Gabriel was joined by an army of angels, and they sang in praise of God and peace on Earth.